1. Field
The present disclosure relates to a system and method for animating a computer generated character in real time through a single person performance.
2. General Background
Creating computer animated performances for use in television and movies can be an extremely time consuming process. In a current approach for animating a computer generated character, motion capture is used to record a performer's movements. Further, the character's body is animated based on the recorded movements. The performer typically wears a motion capture suit having a plurality of markers, each of which are usually located near a joint to identify the motion by the positions or angles between the markers. The markers, which may be acoustic, inertial, light emitting diode (“LED”), magnetic or reflective markers, or combinations of any of these, are tracked by sensors and/or cameras. Computer software translates the positions, angles, velocities, accelerations of the markers, thereby providing an accurate digital representation of the motion of the performer.
In entertainment applications, motion capture can reduce the costs of animation which otherwise requires the animator to draw each frame or with sophisticated software that interpolates key frames. While motion capture saves time and creates more natural movements than manual animation, it is limited to motions that are anatomically feasible. Furthermore, certain movements such as facial expressions can be difficult to capture using conventional motion capture systems. Therefore, motion capture cannot be used alone to animate an entire character.
U.S. Pat. No. 6,377,281 describes a method and apparatus for creating computer graphical character performances and is hereby incorporated by reference in its entirety. In the method and apparatus disclosed in U.S. Pat. No. 6,377,281, performer movement information is received at a computer from a manual input device that receives live manual manipulations from a performer. Generally, the manual input device includes a plurality of position transducers, such as analog position transducer potentiometers mounted in a mechanical assembly that simulate the motions used by a puppeteer to manipulate a conventional puppet. The mechanical elements or physical controls are directly manipulated by a performer, and the electromechanical transducers convert mechanical motion of the mechanical elements into proportional electrical signals.
For example, the hands of a performer are received in left-hand and right-hand mechanical assemblies that include levers, rotatable shafts, tiltable plates, and related equipment. The mechanical assemblies may include a gyro waldo, stick, arm waldo, etc. The mechanical assemblies can be manually manipulated through a range of positions that are homologous to the positions through which the hands of a performer move when manipulating a conventional hand puppet, electromechanically actuated puppet or other artificial creature. For example, the mechanical input device may include one or more joysticks, data gloves, pushbuttons, or other elements to receive mechanical movement and generate electrical signals.
Animation of a typical character performance usually requires a team of people to coordinate the performance. Generally, a first performer (called a “puppeteer”) provides input movements to such mechanical input devices to control facial expression and head movements. Further, the first performer can provide voice for a character. A second performer provides body movements for the character through a motion capture system. The two performers have to work together to coordinate movements. The movements are used collectively to create a single animated character.
The equipment used in generating the facial expressions can be quite bulky and tends to be stationary. Therefore, at least two performers are required to generate a computer animated character performance.